Top cloning experts gather in South Korea for clandestine test

Top cloning experts from Britain, South Korea and the United States working on ways to use stem cells to treat incurable diseases gathered here to kick-off a week-long secret experiment.

The scientists were led by South Korea's Hwang Woo-Suk, Gerald Schatten of the University of Pittsburgh School of Medicine, and the creator of the cloned sheep Dolly, Professor Ian Wilmut of Scotland's Roslin Institute.

They would not say what the experiment would be about, but said it was expected to be over early next week.

Schatten however told journalists it would be a scientific "milestone" and indicated it could be aimed at combining achievements made in cloning and stem cell research to develop ways to treat incurable diseases.

Hwang, a professor at Seoul National University, and Schatten are co-authors of a landmark study published in May in which they said they had produced "therapeutic" stem cells.

These stem cells carry the identical genes of patients because they are extracted from cloned human embryos produced by combining adult cells from the patients and human eggs from donors, the scientists said.

This means they will not be rejected by the patients' immune systems, they said.

Hwang's team also took a significant step forward in inter-species organ transplants in May.

The team found ways to prevent monkeys rejecting organ transplants from pigs, paving the way for the use of animal organs and cells in humans to replace cells ravaged by illnesses such as Parkinson's and diabetes.

But Hwang cautioned it would take a long time before this process could be applied to treatment purposes, noting technology to control the direction of the growth of stem cells was unavailable.